SAINT-JEAN-DE-MAURIENNE, France — Chris Froome is halfway through the Alps, the last obstacle to his second Tour de France victory, after comfortably maintaining his race lead on a Stage 18 won in style by Romain Bardet on Thursday.

Bardet rode alone down the huge Glandon pass and up the 18 hairpin bends of the previously unclimbed Montvernier Laces to take a solo victory at Saint-Jean-De-Maurienne on the second of four days in the Alps, the last big test before the finish in Paris on Sunday.

As they did on the first Alpine stage on Wednesday, Froome’s rivals again tested the Team Sky rider but couldn’t make him crack over seven climbs.

Two-time champion Alberto Contador showed spirit, with a burst of speed on the climb up to the Glandon pass, but he couldn’t claw back the minutes he lost on Wednesday in a crash.

“One of the hardest days for me,” Contador said. “I was in pain.”

Froome, Contador, and other podium contenders finished together in a group of 10 riders who rode in three minutes behind Bardet, who was too far down the overall standings to have ambitions for the podium this year. But, at age 24, the second French stage winner confirmed the idea that he is a big talent for the future.

Bardet rode away at the top of the punishing Glandon climb — the hardest Alpine ascent so far — and built a lead on the long descent. He held it up the Montvernier Laces, where the road spaghettis back and forth in a spectacular series of switchbacks.